Dual endovascular filter and methods of use

ABSTRACT

Blood filter devices and methods of use.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. §371 ofPCT Application No. PCT/US2010/043390, filed on Jul. 27, 2010, whichpublished in English as WO 2011/017103 A2 on Feb. 10, 2011 and whichclaims priority benefit of U.S. Provisional Application No. 61/228,703,filed Jul. 27, 2009, entitled “Dual Endovascular Filter and Methods ofUse,” the entire contents of which applications and publication areherein incorporated by reference in their entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND OF THE INVENTION

Endovascular procedures are being used more and more frequently to treatvarious cardiac and vascular surgical problems. Blocked arteries can betreated with angioplasty, endarterectomy, and/or stenting, usingminimally invasive endovascular approaches. Aneurysms can be repaired byendovascular techniques. Another use for endovascular surgery is thetreatment of cardiac valvular disease. A common problem in endovascularcatheterization is that plaque found in the diseased vessels and valvescan be dislodged and result in embolization. A major drawback toendovascular treatment of cardiac valves and arteries in the heart orthoracic aorta is that the dislodged debris can embolize into thecarotid vessels resulting in catastrophic consequences such as stroke oreven death. Attempts have been made to protect the cerebral vasculaturewith filters and other devices, but the inadequacy of the present art isobvious in the fact that these devices are rarely used. The pendingpatent applications for such protection devices suggests both theinadequacy of the present art and the need for improved devices not todeflect the emboli but to capture and remove the emboli from the body.

The majority of devices described are filters. The problems with filtersinclude difficulty in placement and retrieval as well as the possibilitythat a filter will fill abruptly causing blockage of the artery prior toremoval of the filter. Cerebral protection requires placement of filtersin the carotid arteries, which has the additional drawback ofmanipulation of the carotid vessels during filter placement while thecerebral vasculature is still unprotected. The risk of stroke for acarotid arteriogram done by cannulation of the carotid artery is 1%compared to an arteriogram done from injection into the aorta withoutselective cannulation which carries minimal risk. The risk ofcannulating a carotid artery, navigating a catheter containing a filterinto position, and deploying the filter would likely carry an evenhigher stroke risk. Patients requiring cardiac or aortic arch proceduresare high risk candidates for having carotid disease. The chance ofcausing a stroke by the placement of the protective device into bothcarotid arteries makes the risk of using these devices prohibitive. Thetime and skill necessary to selectively cannulate both carotid arteriesfor filter placement has also contributed to the decision not to usethem despite the stroke risk of unprotected cardiac and aortic archprocedures.

BRIEF DESCRIPTION OF THE INVENTION

The present invention comprises an embolic filter device. In use, theinvention is placed into the aortic arch by the access via right-radialor brachial enrty, preferably through the right arm but it may also beplaced via the femoral artery or other access point used byinterventional procedures such as the carotid artery. In one embodiment,the device is deployed partially in the aortic arch but also in theinnominate artery and carotid artery. Additionally or alternatively, thedevice may deploy to protect the left subclavian artery, where thedevice is opened and pulled back into position to cover the ostia ofboth the brachiocephalic and left common carotid arteries. A portion ofthe device, typically extending from a common hinged frame protrudesinto the vessel(s) with a portion of the device entering into the vesselor artery to trap emboli. In some embodiments the portion of the devicearising from the common frame has a cone, funnel or other shape adaptedor configured for positioning within the vessel lumen to filter emboli.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 depicts a schematic version of the filter device extending fromthe delivery catheter.

FIG. 2 depicts the filter device delivered and protecting theinnominante artery and the left common carotid artery with the selfexpanding frame and the dome filter material protruding into eachvessel.

FIG. 3 depicts the device being closed and capturing the embolicmaterial within each dome filter.

FIG. 4 depicts the domes closed at a common hinge point to trap theembolic material within the filter and ready to be withdrawn from thebody.

FIG. 5 depicts the filter device being drawn back into the catheterready to be removed from the body.

FIG. 6 illustrates a filter positioned within the aorta and connected toa locking device (unlocked configuration).

FIG. 7 illustrates the filter of FIG. 6 after tensioning the filter intoa sealing arrangement within the aorta and protected vessels andrestraining the filter with the locking device (locked configuration).

FIG. 8 illustrates a variety of exemplary shapes, sizes, andconfigurations of holes that can be formed in one or more of thefilters.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, filter device 100 of the present invention ispositioned prior to any manipulation of the heart or thoracic aorta.FIG. 1 illustrates the filter device 100. The filter device 100 includesa frame 105 having a hinge or collapsible joint 110. The frame 105 has agenerally circular shape that contains two filter portions 115, 130. Thefilter portions 115, 130 extend out of plane with the frame 105 intoshaped sections 120, 135. The size, shape and filter characteristics ofthe filters 115, 130 and shaped sections 120, 135 may vary based on anumber of factors such as the size, shape and relative position of theone or more vessels to be protected by the device 100 as well as theparticle size selected for filtration and the desired amount of bloodflow through the filter 100. These and other details of the componentparts, various embodiments and uses for embodiments of the filter 100are described below.

The device 100 is simple to place and carries only the risk ofcatheterizing the aorta through the arm or leg, which is minimal. In useas shown in FIG. 2, the device is opened in the thoracic aorta andpositioned to cover the ostia of both the inominant and left commoncarotid arteries and at least a portion of the device will partiallyenter the inominant and left common arteries. In the illustratedembodiment all or a portion of the shaped sections 120, 135 are withinthe protected vessel or vessels. This position prevents clots or debrisfrom entering the cerebral circulation through either the right or leftcarotid arteries with one simple device. Any debris from the cardiac oraortic procedure is captured in the paraboloid of revolution shape 120,135 protruding into each vessel from the filter 100.

After the procedure is complete, the device is inverted by means of asheath extended over the catheter wire, which then wholly or partiallycovers the inverted device prior to withdrawal. As shown in FIGS. 3, 4and 5, should any clot or debris be captured in the paraboloid ofrevolution 120, 135, the clot or debris will be captured when invertedvia common hinge point 110 and withdrawn along with the device 100. Theprotrusion or depth of vessel entry of the shaped sections 120, 135 intoeach of the vessels may vary depending upon a number of factors such asexpected particle or emboli size, amount or interaction with the filter100. In one specific example, the shaped section portion of the filterextends from about 0.5 centimeters to about 3.0 centimeters measuredfrom the device frame 105 positioned in the aorta. The material 115, 130protruding into the vessel could be any suitable vascular filtermaterial. For example, filters 115, 130 may be formed from, with orcontain a polymeric material such as polyurethane with drilled holes forblood flow to the cerebral vasculature. In one aspect, the drilled holescould measure about 100 to 200 microns in diameter but preferably about130 microns in diameter. Alternatively, the filters 115, 130 may beformed from porous material suited to trapping emboli. The material forfilters 115, 130 is selected to allow for adequate filtration where theporous or drilled or formed openings will allow for sufficient bloodsupply to the cerebral vascular system while stopping any embolicmaterial from traveling throughout the body circulatory system. Trappingand removal of embolic particles within filters 115, 130 rather thanmerely deflecting material into the aorta is believed to provide abetter clinical outcome for the patients. Embolic particles simplydeflected back into the aorta will eventually block other blood vesselselsewhere in the body such as the kidneys or lower extremities. As such,embodiments of the device 100 may advantageously be employed to filterout, capture and then remove emboli while also keeping the aortarelatively clear. As best seen in FIG. 2, the frame 110 only remains inthe aorta since the filters 115, 130 extend substantially above theplane of frame 105.

The device is preferably concaved-shape with an adequate area to coverthe ostia of both the brachiocephalic and left common carotid arteries(FIGS. 1 and 2). The filters 115, 130 may be made of a material withpores (100 to 200 micron) or similar openings or permeability to allowthe flow of blood into the cerebral circulation, but able to deflect ortrap particles of a size which could cause a stroke. The edge of theframe 105 is preferably a flexible, porous donut shape allowing a goodseal with the curved aortic wall. In some embodiments, the edge of theframe 105 will preferably contain a nitinol wire ring or otherself-expanding material. The device may have struts or ribs positionedon, in or within frame 105 to assist in the opening and closing of thedevice and to help maintain its position in use. The device may also bemade to open as a result of its construction material, for example,nitinol or polymer, elastically resuming its shape after being releasedfrom its sheath.

When the device is to be closed, a tube or sheath is extended over theguide wire until it engages the device. Next, the device is pulled backso that it inverts and is enclosed in the tube for removal (FIGS. 3 and4). Inverting the device so that the filter openings for each of thefilters 115, 130 assures that no trapped particles within filters 115,130 such as within shaped sections 120, 135 escape into the bloodstream.The components of the device 100 may optionally be constructed ofpolymer, fabric, metal, or a combination of these or other suitablebiocompatible materials. The device may also optionally be equipped withradio-opaque markers or other structural parts which are radio-opaquefor aid in placement guidance and/or positioning within the body.

Another embodiment of the device has a rolled edge.

The device may also have a flat porous edge.

Another embodiment of the device has no struts, but instead has anitinol skeleton.

Another embodiment has multiple wires to position and anchor the device.

Another embodiment of the device has anchors at the edges which help tomaintain its position during the procedure.

Another embodiment of the device is parachute-like, with a ring gasketat its edge. The gasket can be a softer material such as, for examplewithout limitation, a silicone polymer or an inflatable membrane such asa balloon member. The profile of an inflatable gasket is generallyrelatively small and when inflated increases in profile, sealing thecontacted portion surrounding the protected vessels. The inflation canbe pressurized from the handle portion at the proximal end of the deviceexternal to the body with, for example a common endoflator used ininterventional cardiology. The gasket would be held firmly in positionover the ostia of the brachiocephalic and left common carotid arteries.The billowy porous middle section would deflect or trap clot and debrison its exterior surface while causing minimal resistance in the aorta.The middle portion would be inverted as it is removed by pulling onwires attached to its center, capturing any clot stuck to it.

Alternatively, the center of the device may comprise a screen, whichfits more snugly against the aortic wall, with a very small profile,further preventing resistance to downstream aortic bloodflow. Again thedevice would be removed by inversion, capturing any debris stuck to itprior to removal.

The device may be round, oval or rectangular or of another shape toassist in sealing of the edge against the wall of the aorta, coveringthe ostia of both the brachiocephalic and left common carotid arteriesand maintaining a low profile within the lumen of the aorta.

This device could be modified in size in another embodiment in order tobe used to cover the ostia of different vessels.

The device may be coated with materials or pharmalogically active agentsthat prevent or impair clot formation (e.g., heparin or any othersuitable anticoagulant).

The device may be deployed through an artery of the arm, or through thefemoral artery. The preferred method would be through the right arm, ifpossible, as this would allow the device to be pulled back against theaortic wall to place it.

When deployed through the femoral artery, the opening of the devicewould be different and the device would be pushed against the aorticwall over the brachiocephalic and left common carotid openings ratherthan being pulled back. A wire would be cannulated into thebrachiocephalic artery in this case to ensure correct positioning of thedevice. The device would be modified to allow this method of deliveryand positioning. In one aspect, retrieval of the device would involveinversion and closing of the device by drawstring or another method. Forexample, pulling, activating, manipulating or otherwise causing movementof the common hinge or frame joint 110.

Brachial Artery Insertion of the Device

The device is delivered via percutaneous insertion into the rightbrachial artery and is guided into the aortic arch. There it is deployedand then pulled back into position to cover the ostia of the innominateand left common carotid arteries. The device deflects and filtersembolic debris during aortic and cardiac procedures, allowing the flowof blood through into the cerebral circulation (carotid arteries) butnot permitting the passage of particulate debris.

Femoral Artery Insertion of the Device

The device is delivered via percutaneous insertion into the femoralartery and is guided into the aortic arch. After catheterization of theinnominate artery, the device is passed over the wire and brought intoposition covering the ostia of the innominate and left common carotidarteries.

Deployment of the Device via Arm Approach

Percutaneous access to the circulation via the right arm is performedand a wire guided into the aortic arch after exiting the innominateartery. The device may be placed over the wire or advanced without aguidewire and guided into the aortic arch. The covering outer sheathwhich encapsulates the device is retracted, exposing the device to theaortic bloodstream. The device is then opened in the aortic arch. Thedevice is pulled back into position, covering the ostia of theinnominate and left common carotid artery with a portion of the deviceentering into each vessel. The device allows the passage of bloodthrough to the carotid arteries, but deflects debris passing along theaorta and filtering any embolic material entering the innominante andleft common carotid arteries. At the completion of the debris producingconcomitant procedure, the device is closed by inverting the two domes120, 135. The device is then withdrawn into a covering sheath (FIG. 5)to completely encapsulate it prior to removal from the arm accessartery. Any trapped debris is captured in the domes, safely and securelywithin the catheter.

Embolic Filteration Device

The device of the present invention, viewed from above, is semi-circularor oval in shape with an adequate diameter of about 15 mm to about 30 mmin the short axis and about 20 mm to about 60 mm in the long axis tocover the ostia of both the brachiocephalic and left common carotidarteries. The filter material may be a polymeric material such aspolyurethane or other thin material with a porosity that will allow theflow of blood, but capture particles of a size which could cause astroke. FIG. 8 illustrates exemplary sizes, shapes, and configuration ofthe holes that can be formed in a filter. The size and configuration ofthe holes in the filter could be round in shape but more effectivelywould be an oval or a slot configuration where the material capturedwould be smaller but the surface area of the openings could be larger.Other shapes could include triangular or squares to achieve the samefunction. A square hole would provide about 30 percent more crosssectional area for blood to flow while still capturing the samespherical particle size. The edge of the device is a flexible, porousdonut, similar to the edge of a diaphragm, allowing a good seal with thecurved aortic wall. The edge will preferably contain a self-expandingmaterial such as Nitinol. The frame of the device may also includestruts to assist in the opening and closing of the device and/or to helpmaintain its position in the relevant anatomy.

The device is constructed of polymer, fabric, metal, or a combination ofthese materials. The device may be provided with radioopaque markers ormetal parts which are radioopaque.

Another embodiment of the device has a rolled edge. The device couldalso have a flat porous edge. Another embodiment of the device has nostruts, but a nitinol skeleton. Another embodiment has multiple wires toposition and anchor the device. Another embodiment of the device hasanchors at the edges which help to maintain its position during theprocedure.

Another embodiment of the device is parachute-like, with a ring gasketat its edge. The gasket would be held firmly in position over the ostiaof the brachiocephalic and left common carotid arteries.

Embodiments of the filter 100 may be configured for self locking and/orself sealing with or within the anatomy of the filter site. Self lock orself sealing may be accomplished by releasing a stowed filter from asheath or other restraint or otherwise activity or actuating the deviceinto a locked or sealing configuration.

Alternatively, the filter may be released into the vasculature and thenurged into a locked or sealed configuration. In one aspect, a lockingdevice is positioned outside the body that is adapted and configured topermit movement of or adjusted to the filter relative to the filter siteto seal and/or lock the position and configuration of the filter. Whenthe desired position and configuration is achieved the external lockingdevice is used to hold the filter in position and maintain the desiredconfiguration.

In one specific aspect, once the desired filter device position isobtained, a locking mechanism relative to the body could hold tensionbetween the device and the aortic wall to maintain a proper blood seal.This could be achieved by tensioning the connection of the device withinthe body via delivery catheter and a clamp or fixation device betweenthe introducer sheath and tensioned member. A good example of this wouldbe a RHV (rotating hemostaic valve) mounted to the introducer sheathallowing the tensioned connection member to pass through the centrallumen. As the tension is added to the central member the RHV could berotated causing an interference force between the two creating a lockwhere the tension is now carried by the introducer sheath which isexternal to the body and the internal filter device which is held intension along the aortic wall without constant human interaction pullingthe device relative to the introducer sheath now needed. Turning now tothe example of FIGS. 6 and 7. FIG. 6 illustrates the filter deployedwithin the aorta but not yet sealed with the anatomy. A lockingmechanism, here a rotating hemostasis valve, is used to allow movementbetween and lock the relative position of the element connected to thefilter (i.e. a guidewire) and the sheath used to deliver the filter.After pulling the filter into a sealing arrangement with the appropriatevessels, the RHV may be locked thereby securing the filter relative tothe sheath and the entire device relative to the anatomy. The RHV in theillustrative embodiment may be replaced by any suitable locking devicethat provides the adjustment, sealing and securing characteristicsdescribed above.

The billowy porous middle section would deflect or trap clot and debrison its exterior surface while causing minimal resistance in the aorta.The middle portion would be inverted as it is removed by pulling onwires attached to its center, capturing any clot stuck to it.Alternatively, the center of the device could be a screen, which fitsmore snugly against the aortic wall, with a very small profile, furtherpreventing resistance. Again the device would be removed by inversion,capturing any clot stuck to it prior to removal.

The device may be round, oval or rectangular or of another shape toassist in sealing of the edge against the wall of the aorta, coveringthe ostia of both the brachiocephalic and left common carotid arteriesand maintaining a low profile within the lumen of the aorta. This devicecould be modified in size in another embodiment in order to be used tocover the ostia of different vessels. The device may be coated withsomething which prevents clots (e.g. heparin).

Any of the features of the filter devices and methods of use describedherein can be incorporated into any of the filter devices and methods ofuse described in U.S. Patent Publication No. 2010/0179647, U.S. PatentPublication No. 2010/0179585, U.S. Patent Publication No. 2010/0179584,U.S. Patent Publication No. 2010/00179583, and U.S. Patent PublicationNo. 2008/0065145 (and vice versa), all of which are incorporated byreference herein. For example, the disclosure herein includesembodiments in which the emboli deflection element from the PatentApplications recited above is replaced with first and second embolitrapping filters, examples of which are described herein.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription rather than of limitation and that changes may be madewithin the purview of the appended claims without departing from thetrue scope and spirit of the invention in its broader aspects. Rather,various modifications may be made in the details within the scope andrange of equivalents of the claims and without departing from the spiritof the invention. The inventor further requires that the scope accordedthe claims be in accordance with the broadest possible constructionavailable under the law as it exists on the date of filing hereof (andof the application from which this application obtains priority, if any)and that no narrowing of the scope of the appended claims be allowed dueto subsequent changes in the law, as such a narrowing would constitutean ex post facto adjudication, and a taking without due process or justcompensation.

What is claimed is:
 1. An embolic filter device, comprising: adeployment sheath having a longitudinal axis; a frame having a deliveryconfiguration and a deployed configuration, the frame comprising a firstframe portion and a second frame portion; a first filter portion coupledto the first frame portion and a second filter portion coupled to thesecond frame portion wherein the first and second filter portions eachhave an open portion and a closed portion, wherein the open portion isadapted to allow foreign particles to pass therethrough and the closedportion is adapted to trap foreign particles therein; wherein the firstand second frame portions pivot about a joint positioned between thefirst and second frame portions closest to each other, an axis of thejoint extending substantially perpendicular to the longitudinal axis ofthe deployment sheath, thereby pivoting the open portions of the firstand second filter portions towards one another about the axis andreconfiguring the frame into the delivery configuration in which theopen portions of the first and second filter portions face each otherand wherein in the deployed configuration the first and second frameportions are substantially perpendicular to the position of the firstand second frames in the delivery configuration and wherein the openportions face away from the deployment sheath in the deployedconfiguration.
 2. The filter device of claim 1, further comprising anelongate delivery member secured to the frame.
 3. The filter device ofclaim 1, wherein the closed portions of the first and second filterportions extend about 0.5 cm to about 3 cm from the frame.
 4. The filterdevice of claim 1, wherein the first and second filter portions aregenerally dome shaped.
 5. The device of claim 1, further comprising adelivery device through which the frame and the first and second filterportions are adapted to be delivered, and further comprising a lock tolock the frame relative to the delivery device.
 6. The device of claim1, where the frame and the first and second filter portions have anaspect ratio of at least about 2:1.
 7. The device of claim 1, whereinthe first and second filter portions are both concave.
 8. A method ofprotecting a cerebral vasculature of a patient, comprising: advancing adelivery device with a filter device positioned therein through a firstvessel, the filter device comprising a frame and first and second filterportions secured to the frame, wherein the frame has a foldedconfiguration and a deployed configuration; deploying the filter devicefrom the delivery device; positioning the first filter portion relativeto the first vessel such that foreign particles traveling into the firstvessel will be trapped in the first filter portion; and with thedelivery device positioned in the first vessel, positioning the secondfilter portion relative to a second vessel such that foreign particlestraveling into the second vessel will be trapped in the second filterportion.
 9. The method of claim 8, wherein the first and second filterportions each have an open portion and a closed portion, and wherein thepositioning steps comprise positioning the first closed portion in thefirst vessel and positioning the second closed portion in the secondvessel.
 10. The method of claim 9, wherein positioning steps comprisepositioning the closed portions-about 0.5 cm to about 3 cm from theframe.
 11. The method of claim 8, wherein the deploying step comprisesdeploying the filter device from within the delivery device to allow theframe to reconfigure from the folded configuration to the deployedconfiguration.
 12. The method of claim 8, further comprising creating aseal between the first and second vessels and the filter device byproximally retracting the frame into contact with tissue.
 13. The methodof claim 8, further comprising locking the position of the filter devicerelative to tissue.
 14. The method of claim 8, wherein the deployed stepcomprises allowing the frame to reconfigure from the foldedconfiguration to the deployed configuration.
 15. The method of claim 8,further comprising folding the frame from the deployed configuration tothe folded configuration, wherein folding the frame prevents foreignparticles from being released from the first and second filter portions.